Modern integrated circuit devices utilize various solid-state elements such as transistors. Generally, transistors (such as field effect transistors (FET)) include a semiconductor channel region between conductive source and drain regions. The semiconductor channel region in an FET is changed from a non-conducting state to a conducting state based on the presence of a voltage field generated by the gate conductor. Similarly, diodes utilize semiconductor regions to control current flow between the anode and the cathode and, in the same way, bipolar junction transistors control current flow based upon the semiconductor nature of the collector, emitter, and base.
Integrated circuit technology may involve the use of epitaxial silicon carbon source/drain regions adjacent the semiconductor channel regions in N-type field effect transistors. Due to the lattice mismatch between silicon and diamond lattice, epitaxial silicon carbon material in the source drain region imparts a tensile strain to the channel which leads to enhanced electron mobility and N-type transistor drive current. A similar approach in the case of P-type field effect transistors is adopted by using epitaxial silicon germanium in the source drain regions to induce a compressive strain in the channel region which leads to enhancement on hole mobility and P-type transistor drive current. It is therefore desirable to have improved methods and structures for utilizing such epitaxial material regions.